UNIT 4: ANIMAL TISSUE Campbell and Reece, 2010.Chapter 40 p. 856 – 860
WHERE DO TISSUES FIT INTHE LIVING ORGANISM? Life begins as a single cell called a zygoteafter fertilization This cell differentiates into a variety oftissues. (Group of cells with the samefunction) A group of tissues with the same functionforms an organ. Group of organs – Organ system Group of organ systems - Organism
WHAT IS TISSUE?SPECIALIZED CELL of thesame type that perform acommon function in thebody.
MAJOR TYPES OF ANIMALTISSUE EPITHELIAL TISSUE: Covers or linesbody cavity and forms glands. CONNECTIVE TISSUE: Binds differentorgans together and support the body. MUSCLE TISSUE: Movement NERVOUS TISSUE: Senses and transmitsimpulses
SQUAMOUS EPITHELIAL TISSUESTRUCTURE Single layer thin, large, flattened cells Cells have irregular shape and are closely packed inmosaic form. Cells are attached to a basement membrane.FUNCTIONS Diffusion of gasses can occur easily over surface. Supply friction free surface for blood flow. Protects and supports underlying tissue
SQUAMOUS EPITELIAL TISSUEWHERE?•Lining of lungsand blood vessels•In mouth andesophagus.
CUBOIDAL EPITHELIAL TISSUESTRUCTUTE Square cells, closely packed in a single layer. Cells attached to a basement membrane.FUNCTION Absorbs molecules
COLUMNAR EPITHELIAL TISSUESTRUCTURE Tall elongated, column-shaped cells. Nucleus near the base of the cell. Cells are attached to a basement membrane.FUNCTIONS Plays a role in absorption of nutrients. Protects and supports underlying tissues.
CILLIATED CULUMNAR EPITHELIALTISSUESTRUCTURE Comprises of columnar cells with cilia at their freeedgesFUNCTIONS Sweeps impurities towards throat Improves movement of substance through the ducts.
GLANDULAR COLUMNAREPITHELIAL TISSUESTRUCTURE Consist of cuboidal and columnar epithelial cells. Unicellular glandular cells with goblet cells scatteredamong non-glandular cells.FUNCTIONS Produce mucus which serves to lubricate the intestineand make movement of food easier. Keep respiratory passage moist. Secrete enzymes, hormones, sweat, wax and saliva.
GLANDULAR COLUMNAREPITHELIAL TISSUEWHERE?• In smallintestine andrespirativepassages.• Occur insalivary glands,thyroid glandand sebaceousglands in theskin.
LOOSE AREOLAR FIBROUSCONNECTIVE TISSUE Occurs beneath the skinand most epitheliallayers connecting organstogether. Filling the spacesbetween organs andmuscles, around musclesand blood vessels
DESCRIPTION OF AREOLAR- Loosely arranged tissue In jelly-like matrix there are 4 types of livingcells and two types of non-living cells. Macrophages Mast cells Fat cells Fibroblasts Collagen fibres Elastic fibres
FUNCTIONS OF AREOLAR-Areolar tissue binds organs or organcomponents together and supportsstructures.Allows for movement betweenstructures.The matrix allows for diffusion ofsubstances like gases, nutrients,hormones and wastes to and from theblood.
Fibroblasts – secrete collagen and produceelastic fibres. Macrophages – Engulf foreign particles bymeans of phagocytosis to defend the bodyagainst infection. Mast cells – They secrete the matrix, releasehistamine during inflammation, produceheparin (anticoagulant). Fat cells – Synthesis and storage of fats. Collagen fibres strengthen the tissue. Elastic fibres – Allows for expansion andcontraction.
MACROPHAGES, PLASMA CELLSMAST CELLS AND ELASTIC FIBRES
DENDE WHITE FIBROUSCONNECTIVE TISSUE In dermis of skin,tendonsFUNCTIONS:Attach muscle to bones
DESCRIPTION OF DENSE WHITE- Consist of mainly white collagen non-elasticfibres. The collagen fibres are non-elastic,densely packed, arranged in parallelbundles, and has a shiny appearance. Fibroblasts are elongated cells and occurparallel in rows. Minimum amount of matrix.
YELLOW FIBROUS CONNECTIVETISSUE In ligamentsFUNCTIONS: Attach bone to bone Hold bones of a joint inplace. Restrict movement ofbones and preventdislocation duringnormal movement.
DESCRIPTION OF DENSE YELLOW- Consist of white collagen fibres and anetwork of yellow elastic fibres. Ligaments are strong and flexible.
ADDIPOSE TISSUE Found beneath the skin,around heart and otherorgans.FUNCTION: Insulation Stores fat.DESCRIPTION: Large round cells filledwith fat or oil.
HYALINE CARTILAGEWHITE FIBROUS CARTILAGEYELLOW ELASTIC CARTILAGE BONE
HYALINE CARTILAGE Occurs at the ends ofbones in movablejoints. Parts of thelarynx. In the walls of thetrachea and bronchi. In between the ribsand the sternum. On the tip of the nose
DESCRIPTION Contains fine collagen fibres. White translucent matrix. Cartilage tissue is surrounded by a fibrouscapsule called the perichondrium withblood vessels for nutrition. It consists of living cells calledchondrocytes. They occur in small fluid-filled spaces calledlacunae. In the lacunae the cells arearranged singular or in groups.
FUNCTIONS Chondrocytes produce arubber matrix calledchondrin. Reduce friction at joints Attach bones firmly to otherbones. Keeps tubes open (C-shaped intrachea). Forms permanent structures(nose). Longitudinal growth of longbones.
FIBROCARTILAGE Occurs as disks betweenthe vertebrae. Surrounds the edges ofthe sockets of ball-and-socket joints. Between the pubic bonesin front of the pelvicgirdle.
FUNCTIONS It serves as shockabsorbers betweenadjacent vertebrae. It deepens sockets tomake dislocation lesseasy.
DESCRIPTION Contain a large number of collagenfibres. White translucent matrix. Cartilage tissue is surrounded by afibrous capsule called theperichondrium with blood vesselsfor nutrition. It consists of living cells calledchondrocytes. They occur in small fluid-filledspaces called lacunae. In thelacunae the cells are arrangedsingular or in groups.
ELASTIC CARTILAGE In the ear lobe At the tip of the nose In the epiglottis. Septum of nose
FUNCTIONS It maintains the shapeand flexibility of the earlobe and tip of the nose. It strengthens andsupports the ear, noseand epiglottis.
DESCRIPTION Contain collagen fibres and a large network of elasticfibres. Translucent matrix. Cartilage tissue is surrounded by a fibrous capsulecalled the perichondrium with blood vessels fornutrition. It consists of living cells called chondrocytes. They occur in small fluid-filled spaces called lacunae.In the lacunae the cells are arranged singular or ingroups.
COMPACT BONE Occur in the bonesof the skeleton
FUNCTIONS Support Protection Locomotion Red blood corpusclesand white blood cellsare produced in the redbone marrow.
DESCRIPTION The matrix of compactbone consists of collagenfibres together withcalcium, phosphorus andmagnesium. These components arearranged in circles calledlamellae, around theHaversian canal,containing artery, vein andnerve. Contain bone cells calledosteocytes
BLOODPLASMAWHERE? Matrix in which the bloodcells are found.FUNCTIONS: Transport various formedelements to body parts. Dispersion medium. Transports digested food. Transports cellular waste. Transports hormones. Plays a role in regulation ofbody temperature. Transports antibodiesDESCRIPTION Straw color fluidconsisting mainly ofwater with manysubstances in solutionlike nutrients, organicwaste, inorganic saltsand ions, plasmaprotein, dissolvedgases, hormones,enzymes andantibodies.
ERYTHROCYTES (RED BLOODCELLS)FUNCTIONS: Transports oxygen in theblood from the lungs toall living cells. Transports some of thecarbon dioxide from thebody tissues the lungs. Play a role in the clottingof blood. Play a role in theregulating of pH of bodyfluids
DESCRIPTION Small round biconcave disks filled with cytoplasm,but without a nucleus. Contain the red pigment hemoglobin. Hemoglobin contains 4 units, each with theprotein globin and a complex iron-containing,structure called heme. The iron form a looseassociation with oxygen and in this way red bloodcells transport oxygen and readily give it up totissues.
LEUCOCYTES(WHITE BLOOD CELLS)FUNCTIONS: Engulf infections bymeans ofphagocytosis. Produce antibodies. Defense orimmunity of body
DESCRIPTION Larger cells with nuclei. Without staining theyappear transparent. Irregular is shape. – there are5 types of leucocytes basedon differences in size andnuclear shape: Neutrophils Eosinophils Basophils Monocytes. Lymphocytes.
BLOOD PLATELETSDESCRIPTION: Fragments of giant cells,present only in bonemarrow. They are small discswithout nuclei andbounded by a typical cellmembrane. A characteristic feature ofplatelets is their tendencyto stick to foreign surfacesand to each other to formclumps.FUNCTIONS; When blood vessels aredamaged, plateletsform a plug that sealsthe vessel, and injuredtissues releasemolecules that helpthe clotting of blood.
SMOOTH MUSCLE Found wide spread inbody. Found in the walls ofbloodvessels, digestivetract, respiratory ducts,urinary ducts andreproductive ducts. In iris of eye and formsmall muscles attach tohair follicles
FUNCTIONS OF SMOOTH - Control slow involuntarymovements of organsperforming important lifeprocesses e.g. Contractionof stomach wall duringperistalsis. Responsible for themovement of substancesin internal passages e.g.Blood in blood vessels.
DESCRIPTION OF SMOOTH - Every smooth muscle fibre is an elongated, thin cellwith a thick central part and pointed ends. Every cell has a big nucleus centrally situated. This muscle is never connected to bone. Can contract for long with out causing a spasm e.g.Uterus wall during birth.
CARDIAC MUSCLE TISSUE Found only in the heart.
DESCRIPTION OF CARDIAC - Contain many mitochondria, glucose and bloodsupply. Consist of branched cells with one or two centralnuclei. Cells are rectangular and connected with musclebridges. The ends of 2 cells are attached by intercalated disks.
FUNCTION OF CARDIAC MUSCLE It causes the rythmic beating of the heart so that bloodcan flow through the whole body.
NERVOUS TISSUE Nervous tissue is composed of highly specialized nervecells called neurons and supporting cells orneuroglia. The neurons, which are the basic units ofcommunication, react to stimuli and transmit theimpulses (information) form one region of the body toanother. Neurons extend throughout the body and do not actalone.
STRUCTURE OF A NEURON Neurons are usually long, large and complex in shape. It consists of a cell body and several cytoplasmicprocesses. Processes that transmit impulses to the cell body aredendrites and usually are multiple. The single process that transmits impulses away formsthe cell body in the axon. The cell body contains a nucleus, neurofibrills, Nisslgranules, neuroplasma.
Three types of neuronsaccording to structure: Unipolar neurons Bipolar neuronsMultipolar neurons
Three types of neurons because offunction: Sensory neuron Motor neuron Inter-